764
FXUS65 KTFX 291051
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
451 AM MDT Sat Jun 29 2024

.SYNOPSIS...

Dry and seasonable weather is expected today as high pressure
moves through the area. Expect a wetter start to the work week,
with afternoon showers and thunderstorms expected each afternoon
from Sunday through midweek. Warmer and drier weather returns for
the Independence Day weekend.

&&

.DISCUSSION...

Key Points:

-Showers and thunderstorms expected during the afternoons the
first half of next week

-Temperatures will be below average through midweek, with a
warming trend for the end of the week

Short term (through Sunday)... Tranquil and noticeably warmer
weather is expected today as a transient upper level ridge slides
across the Northwestern US. With this ridge and southwesterly flow
aloft, temperatures will rise into the 70s across the Plains,
while some of the Southwestern Valleys will reach the low 80s
under mostly clear skies.

Sunday will be a bit of a more active day across the area as a
shortwave trough moving into the Northwestern US begins to push
into the region, along with a small jet streak. This system will
help to kick off a few showers and thunderstorms across the area,
especially across Southwestern Montana. While atmospheric
thermodynamics will not be overly impressive (CAPE values will
generally be around 1000 J/kg, which is enough for shower and
thunderstorm development but it is not overly impressive), the
overall dynamics of the system may be just enough to allow for the
development of a few stronger showers and thunderstorms with
small hail and gusty winds. SPC does have us in a marginal (1/5)
threat for severe, mainly for the potential for an isolated
instance of 1 inch hail across Southwestern Montana. This seems to
be reasonable, though some of the convective models get a little
excited and show multiple rounds of strong thunderstorms across
the southwest. This seems to be an outlier solution (seems to be
about a 10-20% chance in the distribution), though it is worth
mentioning that conditions could line up for a more
widespread/sustained threat of strong to severe storms tomorrow
across Southwestern Montana.

Extended (Monday through next Saturday)... The first half of the
work week will be strongly influenced by a broad upper level
trough across the Northwestern US, which will keep North Central
and Southwestern Montana on the unsettled side with temperatures
near to slightly below seasonal norms. Expect highs to generally
be in the 70s through the first half of the week with more or less
daily development of a few showers and thundershowers across the
area, particularly over the higher terrain of Southwestern
Montana.

As we move towards the second half of the week, models are in
extremely good agreement (~90%) that upper level ridging will
begin to make its return to the Western US, which will result in
us drying out and rapidly warming up as warmth quickly builds
across the Western CONUS. With this ridging quickly building,
expect temperatures to begin to knock on the 90 degree mark as we
head into the weekend, with warmth likely to continue into the
following week. Ludwig

&&

.AVIATION...
29/06Z TAF Period

Generally VFR conditions are expected to prevail over the CWA
through the period. There are some slow clouds around Lewistown
currently, that should thin out by 08z. Also, there is a small
potential for fog early Saturday morning, but to low of a
probability to have it at a TAF site right now. The next chance for
thunderstorms generally develop after 06z Sunday over Central MT.
Brusda

Refer to weather.gov/zlc for more detailed regional aviation weather
and hazard information.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  75  52  78  52 /   0  10  40  20
CTB  71  50  74  51 /   0  10  50  10
HLN  83  56  83  56 /  10  10  50  40
BZN  80  50  83  51 /  10  10  50  80
WYS  76  43  78  45 /   0  10  30  70
DLN  81  49  80  48 /  10  10  50  50
HVR  73  52  81  55 /   0   0  20  20
LWT  71  47  78  50 /   0  10  40  60

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

http://www.weather.gov/greatfalls